Laundry dryers are typically electric appliances that dry washed laundry, mainly washed clothes, by using high temperature air. In general, a laundry dryer is configured of a drum, a driving source, heating means and a blower unit. Laundry is held in the drum and the driving source drives the drum. The heating means heats air drawn in the drum. The blower unit sucks or discharges the air inside the drum.
Laundry dryers may be categorized, based on a method of heating air that is heating means, into electric-type laundry dryers and gas-type laundry dryers. In an electric-type laundry dryer, air is heated by using electric resistance heat. While, in a gas-type laundry dryer, air is heated by using heat generated from gas combustion. On the other hand, laundry dryers may be categorized into condensation-type laundry dryers and exhaustion-type laundry dryers. In a condensation-type laundry dryer, air is heat-exchanged with laundry in the drum and the damp air is circulated, not discharged outside, to be heat-exchanged with external air at an auxiliary condenser. At this time, water is condensed and discharged outside. In an exhaustion-type laundry dryer, air is heat-exchanged with laundry in the drum and the damp air is directly discharged outside the laundry dryer. Also, laundry dryers may be categorized, based on a method of loading laundry, into top loading-type laundry dryers and front loading-type laundry dryers. In a top loading-type laundry dryer, laundry is loaded into the drum through a top of the laundry dryer. In a front loading-type laundry dryer, laundry is loaded into the drum through a front of the laundry dryer.